Blink
by BlueNeutrino
Summary: Mary's on the run from the Devil and Ciri's on the run from the Wild Hunt in a post apocalyptic world of angels and demons.


**A/N:** **Maybe this crossover is nuts. Maybe it's not. Idk. But I liked it.**

 **As you can probably figure, this is set early SPN season 12, mid-Witcher 3.**

* * *

The ground is treacherous beneath Mary's feet. Her boots pound the dirt, stumbling over the pitching slopes of shale and limestone as the air burns her lungs, throat raw as she struggles to catch her breath. There's no time to rest. She stops, she dies.

It's no longer just Lucifer at her back. Demons, a swarm of them, had crossed her path a mile ago, and only the temporary distraction of the archangel picking them off had allowed her to make it even this far. Eight of them had escaped the melee, and now with Mary in their sights, they're closing in.

Her downfall comes in the form of a grey stone ridge up ahead. She scrambles to the top, muscles burning, and tries to make the jump to the steep slope on the other side. Scree slips, snatches her feet out from under her, and then she's falling. The gravel scratches at her skin, face and knees and elbows screaming as bruises bloom and cuts burn.

By the time she picks herself up at the bottom, they're already waiting for her.

The leader apparent is only meters away, black eyes fixed on her with a menacing glower. " _Human_ ," he spits.

Mary grits her teeth and steels herself to fight. She could try to run, but with the jagged rocks rising so steep around her, she doubts she'd get far. Her fists raise, armed only with sheer determination and Enochian-engraved knuckle dusters meant for angels.

Still, brass knuckles are brass knuckles. Mary flexes her fingers around the grips and readies herself to fight.

The first one steps into range: coal dark hair, a rugged, lined face, and contempt burning in the black pits of his eyes. He's armed. Baseball bat and a beretta. He could shoot, but at least somewhat fortunately it seems like he wants to have fun.

Mary thinks of Dean, thinks of Sam, and vows to do them proud. She swings the first punch. Blood bursts forth where metal collides with the ridge of a cheekbone, and a surge of adrenaline flood her veins. The demon growls in pain, raises his bat in anger, then the second of them is on her too. A machete swings close to her head and she has to duck desperately and scramble back. She isn't sure how many punches she lands before she goes down, but she feels bone crunch beneath her hands with every blow traded, and savors it.

In the end it's too much. Mary hits the dusty floor, fatigued, outnumbered and outgunned. Perhaps this is it. Lucifer won't get the satisfaction.

When she sees the light, she wonders if this is what death looks like in this world. It isn't how she remembers - a cool, eerie green rather than the orange fury of fire. The flash erupts in front of her eyes, leaving luminescent trails across her vision where it darts like a firework, then, one by one, the demons start to fall.

She sees the first of them go down, crying out as blood sprays in a neat line from his his chest before his black eyes spark red, then she sees the blade that caused it as the light solidifies into the shape of a woman, a sword grasped firmly in both hands.

There's barely a second of stillness for Mary to get a glimpse, but it's enough to make a stark impression. The woman's clothing is in odd contrast to the grungy grey wool and dusty leather of the demons' attire. She wears a white shirt under a dark brown leather garment that Mary can't decide is armor or a corset, with brown gloves, brown leather trousers and matching boots, and a pendant in the shape of a wolf head hangs around her neck. Her hair is an icy silver blonde, pulled back in a ponytail that leaves a few errant strands to stir with her movement, while her eyes are sharply defined by black shadow on a pale face. The most striking thing is the wicked crescent scar marring her left cheek, yet nonetheless, her features seem delicate. Delicate and fierce. A sword is strapped to her back - or rather, an empty sheath. The usual contents are currently deployed.

She moves like a dancer, were dancers made of lightning, and if lightning wielded a sword. Every move is fluid, the blade arcing gracefully as it cuts down the demons like a breeze toppling a house of cards. Mary is all but forgotten as they scramble to take on the new threat.

The one armed with a machete rushes the woman from behind, and without even looking she dematerialises in a blink, leaving behind a green trail like a long exposure capture of neon lights that twists and twirls and reforms itself behind the enemy. From somewhere, a gun goes off, but she's gone again before the bullet even finds its target. The scintillating blade buries itself in the throat of a demon to a fresh spray of blood, and another demon goes down with hellfire flashing in his eyes. She's outnumbered, but the odds appear stacked so highly in her favor it hardly seems fair.

Mary watches the fight unfold like she's caught in the blinking lights of a rave. A glowing silhouette appears before her eyes, like the dazzle lingering in the wake of a camera flash, then she sees it again. One, two, three, four times all at once behind each of the demons left standing, culminating in the final flash of a descending sword. The world stops turning for a moment, light fading to leave behind just the woman standing statue still, sword in hand. Then, the next second ticks on and all the bodies fall to the ground.

Mary blinks. She isn't sure what she just witnessed, but a tension she hadn't even noticed before seeps from her chest as she realises she's still alive. There's a scent of sulfur lingering in the air.

The woman sheaths her sword, casts a final grim look over her kills before turning to Mary, still lying beaten in the dirt. She steps forward. "Are you alright?"

In return, Mary gives her a cautious stare. "I think so." Her answer is wary. "What are you? An angel?"

"No." The woman draws closer, offers a hand. "I'm Ciri." Her voice is kind. Genuine.

Mary eyes the proffered hand for a moment longer, then reaches out and takes it. "Mary," she says as the woman helps her to her feet, then dusts herself down. "What was that? I've never seen anything like it."

"It was…" There's a pause. She doesn't seem secretive so much as searching for words. "I have abilities. I saw you, and you seemed to be in trouble. It seemed the time to use them."

Well. As explanations go, it's not the most complete, but not the hardest Mary's had to swallow. "Thank you."

Ciri nods in acknowledgement. Then, her next sentence throws Mary for a loop. "Could you tell me where we are?"

Mary blinks. "You don't know?"

There's a pause. "Don't you?"

They both stare at each other in confusion. Mary shakes her head. "No. I'm not supposed to be here."

"That makes two of us."

"How did you get here?"

Again, Ciri looks like she's carefully choosing her words. "My powers. They allow me to travel to other worlds, or dimensions. Sometimes I can choose the destination, but other times I have to go where the power takes me. When I thought of somewhere I wouldn't easily be followed, this isn't what I had in mind."

It isn't exactly what Mary had in mind, either. Ciri looks at her, brow furrowed, and Mary realises her eyes are green. Shockingly green. She thinks of Dean, and feels a pang. "Wait, you can travel between worlds?"

"I can…"

"Could you help me?" There's a spark of hope that's ignited in Mary's chest. Even the hesitant look on Ciri's face doesn't dampen it. "I came here through a portal. I need to find a way back. To my sons."

The look she gets in return is apologetic. Regretful. But Mary can recognise a definite 'no'. "I'm sorry. It's not that simple. I'm being followed by someone dangerous. Really dangerous, and every time I use my power to traverse dimensions he comes closer to finding me. It would put you in danger too."

"I don't care. I'm already in danger. I _need_ to get back."

Ciri's expression is sympathetic, but that only makes it worse. "There's more than just you at stake. I really am sorry."

She turns away before Mary has chance to insist, begins searching the bodies of the fallen demons. "What were they?"she asks.

"Demons. You've never seen them before?"

"Not like this." She loots the machete and shoves it into her belt before moving onto the next one.

"How did you kill them? That isn't easy."

"Hmm. I tried a new oil on the blade recently. Been trying to adapt to different worlds. Seems to have worked." The gun seems to intrigue her. "What is this?"

Mary holds out her hand for it. "A gun. Give it to me. I know how to use one." Skilled fighter though she is, Mary doubts the beretta would be much use in the hands of someone who seems practically pseudo-medieval.

Ciri considers a moment, frowning, then hands it over readily. As Mary checks the ammo and tucks it into the back of her jeans, her stomach growls.

Ciri pauses looting and looks over at her. "You're hungry."

"Yeah, well. Been here a while. Not much food around."

The younger woman frowns. She reaches for the satchel tied to her belt and rummages inside, then holds out something to Mary wrapped in a piece of red cloth. "Here." Curious, Mary unwraps it to find it's pieces of honeycomb. When she looks up again, Ciri is offering her a bottle. "Health potion. The original recipe was kind of toxic, but I picked up a few new ingredients while I've been traveling; made a few changes. Was saving it for an emergency, but it seems you're more in need of it than me. Try it. It will help."

"Potion, huh?" She sounds wary, but she's already made the decision to trust Ciri as she accepts it and gives it a sniff. It doesn't really smell of anything. Doesn't taste of much either as she gulps it down, then starts to chew on a few bites of honeycomb. The effects take hold rapidly, the pain from her myriad injuries dulling and the gnawing ache in her gut starts to ease. Ciri's right. It helps.

"Thank you." She finishes off the whole thing before Ciri even starts examining the next corpse. "I'm grateful for your help. Truly. But are you sure there's nothing you can do to help me get home? My boys...they probably think I'm dead. I need to see them again."

Ciri straightens up once more and fixes her gaze on Mary. The 'no' is waning. Mary can tell. "I know how hard it is to be away from family," Ciri says. "If there's any way I can help you get back to your sons, I will. But I need time to make a plan. Travelling between dimensions isn't easy."

For now, that's good enough. A smile of gratitude has begun to curve on Mary's lips when a rumble of thunder sounds in the near distance. Immediately, both women look up, eyes drawn to the patch of sky where the already grey cloud is rapidly growing darker. Mary thinks she sees the silhouette of wings as a flash of lightning illuminates the clouds. " _Shit_."

"What is it?" Ciri says as Mary grabs her arm and tugs on it urgently.

"We need to go," Mary says. "You aren't the only one being hunted." Her feet resume the familiar _thud thud thudding_ into the ground, and they run.

Ciri's fast. Like lightning, as Mary's already seen, but she doesn't leave Mary behind. The pair of them come upon a steep bank of rock and begin to climb, loose shale sharp beneath their fingers as they help each other up. Ciri glances back over her shoulder, eyes widening when she spies more lightning flashes and the shadows of wings. "What's hunting you?" she shouts over the rumbling thunder, and Mary swears she feels the flutter of wingbeats stir her hair, far too close.

"The Devil," Mary says.

"What's that?" Ciri reaches the top of the slope first, turns to help the other woman up, and Mary's stomach turns to lead as she emerges over the crest. Her mouth has gone dry. She stares, stony faced, at a spot over Ciri's shoulder.

"That."

Ciri turns.

Not ten yards away, Lucifer stands. His head tilts to one side, a mocking smile twisting on his face. "Mary." The word oozes menace. "Didn't think that little scuffle would keep me occupied for long did you? I see you've made a friend. Well, isn't that adorable." He saunters forward, and there's a ring of steel scraping on leather as Ciri draws her sword. She looks confused, but nervous.

Lucifer rolls his eyes. "Please." He raises an arm, drawing the moment out, then gives a flick of his wrist. Ciri falls.

Mary hears her cry out as she goes down, tumbling back down the slope they've just mounted. A yell leaves Mary's own mouth, calling out after her, but she doesn't get chance to see if Ciri's even conscious when she reaches the bottom. Lucifer is next to her, his hand reaching for her throat.

Mary goes for the gun. She makes it, drawing and shooting fast enough to offload a round into his gut at point blank range, but all it gets her is a scowl of irritation. His grip closes on her wrist, wrenching it roughly behind her back, and a cry of pain leaves her lips. Her fingers go numb, the beretta tumbling from her grasp. The next thing she feels is a crushing pressure across her windpipe.

"Did you really think I'd let you escape?" Lucifer leers, forked tongue waggling as he savors the moment. Mary feels the air leave her lungs just as her feet leave the ground.

What little strength she has left is rapidly draining, but she clings to consciousness long enough to see the flash of green behind him. A tiny smile tugs at her own lips.

Then, instead of the forked tongue protruding from Lucifer's mouth, the tip of a steel blade emerges between his teeth.

Immediately, he lets Mary go, eyes flying wide as they focus on the bloodied point driven through the back of his skull. Just momentarily, he sways on his feet, surprise playing out on his face. Then it turns to anger.

Ciri wrenches the blade out. Lucifer spits, blood spills over his chin, and murder flashes in his amber eyes. He rounds on Ciri, and Mary can see the wound in the back of his head has already healed beneath the blood-matted hair. "Rude," he says, then raises a hand, fingers ready to snap.

"No!" Mary screams.

The air turns cold.

The suddenness of it is enough to be a distraction. Lucifer pauses, hand in front of face, watching as his breath mists in the air. Snowflakes float down to settle on his fingertips. Even for here, it's weird. "What the Devil…"

Taking advantage of his distraction, Mary scrambles up and runs to Ciri, whose face has suddenly turned ashen. She stares up at the sky.

There are more fireballs incoming. They haven't exactly been uncommon since Mary got here - such a meteor storm was what allowed her to escape Lucifer the first time - but this time it's different. There are more than just angels filling the skies. The ominous shadows of wings flicker overhead, but low on the horizon Mary sees other shapes: horses and riders, skulls and swords, armored soldiers advancing. Lucifer appears to have noticed them too. It takes her far too long to realise they're more than just shadows.

Ciri's hand closes around Mary's wrist. "Mary, come on! Let's go."

The first of the fireballs begin to land. They run.

As they dodge the impact of a meteorite off to their left, Mary takes the chance to glance back, close enough to discern the figures rapidly advancing on the spot where Lucifer still stands. A hulking giant of a man - if man is even the right word - approaches in front, clad all in black armor, a menacing spike-crowned helmet on his head. His face is obscured behind a skull-shaped mask.

"The armies of Hell sure take image seriously here," she faintly hears Lucifer quip. "Or are you Heaven? I genuinely can't tell."

The figure says nothing, but hefts his sword as he continues to advance.

"I'll take it that's Heaven, then," Lucifer says. He raises a hand, readies to snap his fingers…

And gets only a sword to the face for his efforts.

"Mary!"

Mary's attention is suddenly jerked away by Ciri's voice. The woman pulls her roughly to the side just in time to avoid the impact of another fireball, and Mary stumbles into her, dazed, then quickly recovers. More figures appear around them. Angels, or at least Mary thinks. Hopes. Fears.

It shocks her when Ciri places two hands on her shoulders and roughly pushes her away. "Mary, go!"

Mary blinks. "Ciri…"

"It's me they're after. You need to get out of here."

"Lucifer will keep them occupied. We have a chance. It's safer if we stick together."

Ciri shakes her head. "You need to get back to your sons. I won't lead them right to you."

A whistling sounds in the air, sharp and high pitched above the sound of thunder. Around them, a full on battle is unfolding, though between what, Mary isn't sure. Angels? Demons? Something else?

Ciri shoves her again, hard, and Mary falls back just in time to see a fireball hurtling towards the spot where she'd just stood. "Ciri!"

There's a green flash, hitting Mary's eyes just at the moment the fireball collides with the ground. Mary throws up her hands to shield her face. When the dust clears, Ciri's gone. She doesn't reappear.

Caught in a moment's indecision, Mary hesitates. She should leave, but there's still a part of her clinging to the hope that the woman who might be her ticket home will rematerialise at any moment. Maybe if she blinks her eyes Ciri will be there...

It doesn't happen. Mary glances behind again, sees the fight underway between Lucifer and the invaders, and realises the tides are turning. If Ciri's truly gone, then she's never going to find another way back home if she's dead.

The distraction won't last forever. Mary seizes the opportunity. She turns, fixing her sights away from the battle and ignoring the ache in chest at the hope that's been lost. Then, with an agonizing sense of deja vu, she picks up her feet and runs.


End file.
